Most people kind of know what a firewall is. It’s like a super doorman that protects your network and computers. Right?
Absolutely; a firewall is a piece of software (or hardware) that keeps any eye on your network traffic. In your office, the firewall will sit between your inner trusted network and the non-trustable internet network.
In short, a firewall will protect your network against unauthorized access.
Its sole purpose is to establish a block between your office network and traffic from external sources with the sole purpose to block malicious traffic.
Firewalls spend their time analysing all incoming traffic based on pre-set rules; which you can amend. They then filter in-coming traffic to prevent any potential attacks. In this way your firewall will guard all traffic at your office’s entry point, also known as ports. These ports are where information is exchanged.
As indicated above, your firewall can either be a piece of software or actual hardware; it can be both. A software firewall is typically installed on each of your office’s computer. A hardware one is a piece of physical equipment installed between your office’s network and router.
The most common firewall is where it examines each packet and checks then against your established security rule set. If packets match those of an “allowed” rule on the firewall, then it is trusted to enter your office’s network. There are two types of packet-filtering firewall: Stateful and Stateless.
- Stateless firewalls examine packets independently of one another which makes them easy targets for hackers.
- Stateful firewalls remember information about previously passed packets and are far more secure.
Other types of firewalls include:
- Proxy firewalls
- NAT firewalls
- SMLI firewalls